It’s not Iowa or New Hampshire, but Maryland’s primaries do matter this year, both at the presidential level and down-ballot.

In the White House contest, Republicans are battling to claim the state’s valuable 37 delegates. On the congressional front, the newly competitive 6th District is playing host to heated matchups on both sides of the aisle, while several Republicans are battling for the right to face Sen. Benjamin L. Cardin (D) in November. Here are five key questions about Tuesday’s primaries in the Old Line State:

Why is Rep. Roscoe G. Bartlett’s district suddenly up for grabs?

Bartlett, a Republican with a mostly conservative voting record, has held the 6th District with relative ease since he was elected in 1992. But when Democratic leaders in the General Assembly redrew the congressional map last year to reflect the results of the 2010 Census, they decided to target Bartlett’s seat.

The new congressional map lops off what had been the eastern portion of Bartlett’s district — the counties running along the Pennsylvania border in north-central Maryland — replacing them with the western half of Montgomery County.

As a result, the seat has transformed from one in which voter registration and electoral history long favored Republicans to one in which Democrats are now viewed as having a prime pickup opportunity.

(Lincoln Agnew /For The Washington Post)

Who’s running for the seat?

Because the district is viewed as in play for the first time in recent memory, both parties are staging competitive primaries in the 6th District.

The Democratic contest has been especially heated, with state Senate Majority Leader Robert J. Garagiola (Montgomery) and financier John Delaney engaged in a close and mostly negative campaign. Three other Democrats — Air Force physician Milad Pooran and lawyers Charles Bailey and Ron Little — are also running for the seat.

Garagiola, for whom the seat was reportedly tailored by Annapolis Democrats, has collected the support of unions and many traditional liberal groups. Delaney has the backing of former president Bill Clinton and enjoys a financial advantage based in part on his considerable personal wealth.

On the Republican side, Bartlett is gunning for an 11th term despite some rumbles from his party that he should have considered retiring.

The incumbent faces seven challengers for the GOP nod, the best-known of them being state Sen. David R. Brinkley (Frederick) and Del. Kathryn L. Afzali (Frederick). Although they have argued that it’s time for a change, Bartlett still enjoys the advantage of being much better-known, even in a redrawn seat.

Are there any other competitive congressional races?

There are crowded fields of candidates in almost every district in the state, because it’s relatively easy to get on the Maryland ballot. Four Republicans are vying to face Rep. Chris Van Hollen (D), for example, and five are gunning for the GOP nod against Rep. John P. Sarbanes (D).

But because of the way the new districts have been drawn, Bartlett appears to be the only incumbent in the state who faces a real chance of losing in November. Freshman Rep. Andy Harris (R), who won his Eastern Shore-based 1st District in a tough 2010 race, has been made much safer under the new lines.

Is Cardin going to win another term?

The incumbent Democrat is viewed as the heavy favorite to prevail, both in the primary and in November.

Cardin does face a challenge in the primary from state Sen. C. Anthony Muse (Prince George’s), who has argued that Maryland needs a better voice on Capitol Hill and that African Americans are sorely lacking in the Senate. But Cardin has the backing of President Obama and most of the state Democratic establishment.

The 10-candidate Republican field is led by former Secret Service agent Daniel Bongino and former Bush administration official Richard Douglas. Either would be considered a clear underdog in the general election, particularly given Cardin’s fundraising edge.

Who will win Maryland’s delegates in the GOP presidential race?

As has been the case in many other states, former Massachusetts governor Mitt Romney appears to have the most campaign infrastructure in Maryland among the Republican field. There are 37 delegates up for grabs — three delegates apiece from the state’s eight congressional districts will go to the winner of each district, 10 will go to the statewide vote leader and the last three are controlled by state party leaders.